The website was billed as a place for users to share online reviews, similar to those for restaurants or house painters.

But the site seized by federal authorities this week offered decidedly more lurid content: reviews of strip clubs, massage parlors, escorts and even menus of sexual services.

On Wednesday, a Rocklin woman, one of the alleged operators of an adult website known as myredbook.com, was arraigned in San Francisco federal court on charges that included using the Internet to facilitate prostitution – an enterprise that allegedly netted millions of dollars.

U.S. Attorney Melinda Haag of San Francisco said Annemarie “Maddie” Lanoce, 40, who entered a not-guilty plea and was released on a $250,000 unsecured bond, worked with Eric “Red” Omuro of Mountain View running a website that purported to provide “Escort, Massage, and Strip Club Reviews.”

That description was a masquerade for the site’s true intent, Haag said in a news release. Instead, the website hosted advertisements for prostitutes that included racy photos, lewd descriptions, hourly and nightly rates and customer reviews.

The website used acronyms for various sex acts that could be purchased. So that customers could understand what was being offered at what price, the website, according to federal authorities, defined the sex acts in a “Terms and Acronyms” section.

Arriving at her Rocklin apartment complex Thursday in an SUV, Lanoce decline to speak to reporters. She is due to appear July 10 for a status conference before U.S. District Court Judge William H. Orrick in San Francisco. Omuro is due to appear before U.S. Magistrate Nathanael Cousins on July 2.

Omuro, who also pleaded not guilty and was freed on a $500,000 unsecured bond, was additionally charged with 24 counts of money-laundering in connection with two dozen banking transfers, ranging from $90,000 to $275,000 each. The indictment seeks the forfeiture of nearly $5 million allegedly reaped through facilitating prostitution on myredbook.com and a related site, sfredbook.com.

Legal observers and academics who have researched Internet sex services say convictions are often difficult to obtain in such cases because of federal and state laws protecting website owners or operators from liability for online content submitted to sites by users.

Sacramento attorney and former U.S. prosecutor Bill Portanova said the indictment in the case signals that authorities were meticulously tracking financial transactions to build a case that Omuro and Lanoce were personally profiting as a result of prostitution services arranged through the websites.

“To try to go after the website operator for the content of the website is tricky, no doubt about it,” Portanova said. “If someone is running an online operation and claiming to be removed from the First Amendment expressions of their clients, that’s one thing. But a good investigation can follow a money trail and bring you right into a conspiracy to participate in the online activity.”

Although the website could be accessed for free, myredbook.com listed fees for choice placement of prostitution advertisements and for “VIP Memberships,” authorities said. The VIP memberships allowed customers to enter “private forums” and increased their ability to search reviews of prostitution services, the U.S. attorney alleges.

Scott Cunningham, a Baylor University economics professor who has studied the nexus of technology and prostitution, said sexual service sites often operate as provocative online community forums where users – most often male – exchange information on escorts, prostitutes and other sex workers. The sites are also often vehicles for prostitutes to screen clients in a virtual red-light district.

Efforts by authorities to prosecute prostitution-related activity in a new-technology world have stumbled in some high-profile cases.

In 2012, authorities in New Mexico were frustrated when prosecutors sought to bring a case against former University of New Mexico President F. Chris Garcia and retired Fairleigh Dickinson University physics professor David Flory for allegedly running a prostitution website called “Southwest Companions.”

Authorities said the site allowed up to 14,000 members to solicit and arrange services from prostitutes. But prostitutes weren’t paid through the website, and a state judge ruled that the online service itself didn’t constitute illegal activity.

In Florida, another judge dismissed racketeering and conspiracy charges against a Tampa-based escort site, called Bigdoggie.net, that published escort reviews and provided an online conduit for customers seeking sexual services.

Cunningham said authorities may face a continuing challenge because traditional laws written to target prostitution may not address “any concept of these new Internet institutions.”

“Sometimes, the laws simply don’t exist yet,” he said. “Prostitution is illegal, but that’s not what this is.”

Authorities say the myredbook.com investigation, undertaken by the FBI’s San Francisco field office, the Internal Revenue Service and the Oakland Police Department, grew out of a national crackdown on child sex trafficking this month. Authorities say 168 children have been rescued and 281 alleged pimps arrested as a result of that effort.

Myredbook was recently in the news in connection with the arrest of former California Department of Forestry and Fire Protection Battalion Chief Orville “Moe” Fleming. Fleming is charged with killing his live-in girlfriend, Sarah Douglas, 26, on May 1 in their south Sacramento County home.

Investigators said Fleming had contact with many escorts he met through myredbook. Authorities previously said Douglas was working as a paid escort when she met Fleming two years ago.